Baltimore hit 90 degrees Wednesday for the first time since September, breaking a record set in 1913. More record-breaking heat, and poor air quality, are forecast Thursday.

Baltimore-Washington International Thurgood Marshall Airport hit 90 degrees at 3:21 p.m., according to the National Weather Service. The last time it got so hot in Baltimore was Sept. 27.

Highs are forecast around 90 degrees again on Thursday, potentially matching a record high of 91 degrees, also set in 1913.

A "Code Orange" air quality alert is in effect Thursday for a second day in a row. The Maryland Department of the Environment issued the air quality warning for Baltimore and surrounding counties, cautioning that sensitive groups including children, the elderly, and anyone with asthma, heart disease or other lung diseases could have difficulty breathing.

“The effects of air pollution can be minimized by avoiding strenuous activity or exercise outdoors,” officials said.

Photos of weather in Maryland in 2018.

Sunshine and heat accelerate production of smog by triggering chemical reactions between emissions from vehicles, power plants and smokestacks and natural compounds in the air.

Only light winds are in the forecast, at 5-10 mph from the southwest, to disperse the pollution.

Similar heat is forecast Friday before temperatures drop back into the 60s and 70s for the weekend.